ACE Protocol: Why AC Snoop channel dont have ID,just like AR/AW channel?the meaning of deleted ID is what ?

ACE Protocol:  Why AC Snoop channel dont have ID,just like AR/AW channel?

  For example: 

      there is M1,M2,M3. 

      if   M1 and M2  readunique the same Cache Line X, innterconect need send snoop request to M2/M3 for M1, and send request to M1/M3  for M2.

       the specification ask the the first two snoop M2/M3 for M1 first ,then M send RACK, the innterconnect will process the request to M1/M3 for M2. 

Question1:  the M2/M3 snoop request can be outstanding or not ?

 Queston2:   if interconnect send snoop request to same snooped-master ,the request can  be outstanding or not ?

                     if they can be outstanding , the snooped-master process snoop request should not out of order. is it right?